The statement, which also appeared at the top of the burger chain's China website, underlines the sensitivity to potential food safety concerns in China, one of the most important markets for McDonald's and rival Yum China Holdings.

he firm, which spun off from Yum Brands Inc late last year, said same-store sales rose 3 percent in the second quarter of 2017, driven by a 4 percent jump at fried chicken chain KFC. Pizza Hut's same-store sales were flat.